Automatic train-stop



l. L. DAWSON.

AUTOMATIC TRAIN STOP.

APPLICATION FILED JULY 26,1920.

1,372, 12 2, Patented Mar. 22, 1921.

3 SHEETS-SHEET l.

-1. L. DAWSON. AUTOMATIC. TRMN ST OP.

APPLlCATION FILED JULY 26,1920

Patented m. 22,1921,

3 SHEETSSIIEET2- (hjqabLflawom attotwegf 1. L. DAWSON. Auromm mun sToP,

APPLICATION F|LD JULY-26,1929. V 1,372,122, PatentedMar. 22, 1921.;

SSHEETS-SHEET 3.

Qwuntov Jw'qalrl. Dawm UNITEDSTATES PATENT OFFICE.

JOSEPH L. DAWSON, OF FARMER CITY, ILLINOIS.

AUTOMATIC TRAIN-STOP.

Specification of Letters Patent. Patented Mar. 1921.

Application filed July 26, 1920. Serial No. 398,910.

appertains to make and use the same. i

This invention relates to railway signaling, and its object is to provide means whereby the movement of any kind of a signalinto a position of danger will set an instrument at the trackside so that it will be struck by the arm of alswitch on an approaching locomotive and the switch thrown automatically to actuate mechanism which will close the throttle and apply the brakes.

It is well known that engineers often disregard or fail to see signals which are set at danger, with a result that they pass the same and an accident follows. The signals are usually mounted on posts some distance in advance of the danger point such as a.

railway crossing or a highway crossing at grade, or the signal may be connected with a switch from :themain line onto a siding, or it may be one of a seriesof block signals; but in any case it is set to danger for the purpose of informing the engineer that he must come to a stop; and bv the use ofthis invention the locomotive will be stopped automatically in case the engineer disregards the'signal. y

A special feature of the present invention consists in providing the box or casing of the switch on the locomotive with a hole into which a friableelement such as a glass tube can be inserted behind the switch arm whenthe latter stands in its depending position, so that if the engin er should. runby a signal which isset at danger and the switch is thrown as stated above, the tube will be broken but the locomotive will come to a stop. The engineer will be provided with a given number of these tubes so that he can replace abroken onelandrcontinue on his way, "but at the end of hisrun he will :be calledon to explain whys-11y of them are broken. 1 i A Details of thepreferredembodiment of the connection with a signal terfered with by malicious this invention are set forth below i and shown in the drawings wherein:

Figure 1 is a plan view partly in section 1 of the instrument at the trackside, and Fig. 2 ls a section 011 the line 2-2 of Fig. 1, the

sectional view showing diagrammatically Fig. 3 is an elevation of the switch box with its right side open and its arm in normal vertical position, showing a tube in sectron behind said arm.

Fig. 4 is a vertical section through the casing or box omitting the arm.

Fig. 5 is a perspective detail of the switch arm, its lower end being turned slightly out of line with its body. I

Fig. 6 is a detailof one of the plates within the easing, as referred to hereinafter.

Fig. IS a d agram of the wiring. V In Fig. 21sd1agrammat1cally shown a post P carrying a semaphore signal S. This post stands alongside the track, and when the signal is set at danger the engineer is supposed to stop his locomotive whether it s driven by steam or electriclty, or otherwise. Opposite the post two of the ties T are shown as projecting beyond one rail It, and mounted on sald ties are bearings 1 in which 18 ournaled a shaft 2 having fast thereon a stop 3 providedwith a cross head 4-. which uses alongslde and above the face of the adjacent rail R when the shaft is given a partial rotation. This shaft ex,-

tends beyond the ties and is journaled in collars 5 in the sides of a box or casing 6 which will be mounted on or in the ground alongside the post P, or it may constitute the base of such post. In any event, the casmgshould be closed and water-proof so that the mechanism therein may not be in persons or by the entrance of water. Within this casing a weight 7 issecured upon the shaft in such position that its descent will raise the stop 3, and as seen in Fig. 1 this weight is forked at its outer end. Pivotallyrmounted at 8 between-the fork-arms is an element 9 which is connected with the semaphore S by suitablemeans. As shown in Fig. 2, and up right :rod U leads fromthe semaphore arm S downwardwithin the post and is attached :tojsaid element, but the form of this connection will depend uponthe type of signal.

It is essential to this invention that when the signal is set at danger the weight 7 will be allowed to descend sothat the stop 3 will rise. I prefer a weight to a spring, because it is less likely to get out of order. The illustration is typicalonly of one means whichmay be employed whereby the setting of the signal raises the stop in the track instrument. 7

In Fig. 7 there is shown diagrammatically the adaptation of this invention to a locomotive. In this view the letter A designates the control for the brakes,'as the en- .gineers valve of an air brake system, and

the letter L- designates the engineers control of the motive power, as the throttle lever of a steam engine or the controller of an electric engine. M and M are small electric motors whose shafts are shown as connected with crank wheels W and WV, and the cranks of the latter in turn connect with the controls Land A. The motors are wired in series through a source of electricity such as a battery B, and the wires then lead through a circuit closer or switch C, all being mounted on the locomotive. It is to be understood that when this switch is closed the motors will immediately move to swing the controls so that the throttle willbe closed and the air brakes applied. The switch am in the circuit closer C is to strike the stop 3 when raised by the setting of the signal as abovestated, and the construction of the circuit closer or switch will now be described.

Referring to Figs. 3 to 6, the numeral 10 designates a metallic box'or casing having an opening'il along its bottom and partway up its rear edge, with blocks 12 and 13 at the front and rear ends of this opening;'14= is a partition within this box, and 15 is a door preferably in its front edge by which access may be gained to the interior. One side wall of the box carries a threaded socket or nut 16 into which may be screwed a shaft 17, the same projecting through the partition and being squared as shown at 18 so that plates 19 (see Fig. 6) shaped to fit the'squared portion may be applied to it and attached by screws 2-0 to the partition. Beyond the latter the shaft is continued as seen in Fig. 4, and carries washers 21 and 22, and beyond the latter a nut 23. The

shaft is hollow and notched out as shown at 2 1, andv one wire 25 leads through the top of the box at 26, into the notch, and along the bore of the shaft; while the other wire 27 leads through insulation 28 in the partition 14 and is connected with a copper plate 29 as seen in Fig. 3. i

' Rotatably mounted on the shaft 17 between its washers is a hub 30 on the switch arm 31." The latter stands normally upright as seen in Fig. 3, and the wire 25 is carried up this arm, through it at 32, and

connected with a copper plate 33, this plate during the swinging of the arm traveling on a track 34 until it makes electrical contact with the copper plate 29. The track may well be made of layers of fiber or other insulating material. Below the hub 30 the switch arm extends through the opening 11 in the casing and normally rests against the front block 12 but when it swings to position to close the circuit, it rests against the rear block 13. The lower end 35 of the switch arm is connected with the body thereof by a knuckle hinge 36 as perhaps best seen in Fig. 5, the position of this hinge being such that as the locomotive advances past a set stop 3, said lower end will strike the head 1 of the stop and turn the switch, but if the locomotive backs past a set stop the hinge 36 will permit the lower end of the arm to move over the stop without break- .J:

ing any of the parts.

A striking feature of the present invention lies in the employment of means for detecting the failure of an engineer to observe asignal to stop. use of a friable element such as a glass tube 10 standing just behind the lower arm of the switch when the latter is vertical. This tube is inserted through a hole 41 in one side of the casing as seen in Fig. 1, projected across the space 4-2 to one side of the partition 14: and in which space the switch arm moves, then passed through a hole 43 in the partition, and by preference pushed clear across the casing and its inner end seated in a socket 44 in the other side of the easing. At this time its outer end has passed beyond the outer wall of the opposite side of the casing, and a button 45 or equivalent covering device may be moved over it to prevent its loss. If we assume that it is the rule of the road that the engineer be provided with six of these tubes serially numbered and charged to him, when he reaches the end of a run with less than six, he must explain. A. spring 4L6 bears the lower portion of the switch arm normally to the rear against the tube 10 as seen in Fi 3, and in this position of parts the switch arm stands ready to strike a track instrument or stop which is raised by the setting of a signal. Therefore, unless the engineer stops before his locomotive passes such signal, the switch arm will be moved and the circuit closed so that the motive power will be automatically cut off and the brakes automatically applied, and in the movement of the switch arm a tube will be broken which the engineer will have to explain. If he should pass such signal by accident or in time of fog, when the locomotive comes to rest he can get down and reset the arm and insert another tube, so that he can proceed on his way; but obviously he cannot proceed without r setting the switch so as to break the This consists in the circuit, because as long as the circuit is closed his controls are thrown to cut off the power and to apply the brakes. In order to prevent tampering with this system, the parts will be appropriately housed and locked.

What is claimed is:

1. In a circuit closer for the purpose set forth, the combination with an upright box having an internal upright partition and an opening in its bottom communicating with the space at one side of said partition, a socket within the box at the other side of such partition, a hollow shaft seated at one end in said socket and projecting thence through the partition, the shaft being notched for the admission of a wire, and a nut on its extremity within said space; of a switcharm loosely mounted on the shaft under its nut and with its lower end hanging through said opening for co'action with a switch-throwing element, acontact plate carried b the upper end of the arm and to which sald wire is attached, a curved insulated track carried by the partition, and a second contact plate carried by the track and over which the first is moved when the arm is swung.

2. In a circuit closer for the purpose set forth, the combination with an upright box having an internal upright partition and an opening in its bottom communicating with the space at one side of said artition, a socket within the box at the ot er side of such partition, a hollow shaft seated at one end in said socket and projecting thence through the partition and squared within it, plates attached to the partition and cut to complement each other and to fit said squared portion, the shaft being notched for the admission of a wire, and a nut on its extremity within said space; of a switch arm having a hub loosely mounted on the shaft under its nut and with its lower end hanging through said opening for coaction with a switch-throwing element, a contact plate carried by the upper end of the arm and to which said wire is attached, a curved insulated track carried by the partition, a second contact plate carried by the track and over which the first is moved when the arm is swung, and blocks at the extremlties of the opening in the box for limiting the movements of the arm.

3. In a circuit closer for the purpose set forth, the combination with an upright box having an opening in its bottom, a transverse shaft in the box, a switch arm pivotally mounted on the shaft and with its lower end hanging through said opening, a spring turning the arm on its pivot to swing its lower end to the rear, and a circuit having contacts in the box and on the upper end of the arm whereby it is closed when such arm swings; of a friable element mounted across the box in rear of the lower end of the arm when the latter stands upright, for the purpose set forth.

4. In a circuit closer for the purpose set forth, the combination with an upright box having an opening in its bottom, a transverse shaft in the box, a switch arm pivotally mounted on the shaft andwith its lower end hanging through said opening, a spring turning the arm on its pivot to swing its lower end to the rear, and a circuit having contacts in the box and on the upper end of the arm whereby it is closedwhen such arm swings; of a glass tube for insertion in the box to hold said arm upright against the tension of its spring, the box having openings to receive said tube, and means for holding it in place in said openings.

5. In a circuit closer for the purpose set forth, the combination with an upright box having an internal upright partition and an opening in its bottom at one side of the partltion, the latter and one wall of the box having alined holes and the opposite wall having an internal socket alined with them, a glass tube inserted through said holes with its inner end in said socket, and a button on the wall across the outer end of the tube; of a switch arm pivotally mounted in the box above the front end of said opening and hanging therethrough, the lower end of the arm being connected with the body thereof by a knuckle hinge to permit said end to swing forward but to cause the entire arm to turn on its pivot when struck by a track element, means turning the arm on its pivot normally into contact with said tube, and a circuit having terminals carried by the partition and arm and closed when the latter is swung.

I testimony whereof, I affix my signature, in the presence of two witnesses.

JOSEPH L. DAWSON.

Witnesses:

H. L. BRACKEN, BERT Hmson. 

